North Korean leader Kim Jong Un on July 29 claimed that the entire U.S. mainland is now within reach of his intercontinental ballistic missiles while U.S. President Donald Trump vowed to "take all necessary steps" to protect the homeland.

Kim's statement, carried by North Korea's state news agency, came one day after Pyongyang launched its second test of an ICBM that officials said was more advanced and flew further than the first one, with experts saying it potentially could reach as far as Los Angeles or Chicago.

Kim claimed the test was "perfectly successful" and said it took a great stride toward accomplishing his goal of being able to hit the United States with nuclear warheads.

Trump had earlier called the launch "reckless and dangerous" and warned Pyongyang that its ambitions will backfire.

"By threatening the world, these weapons and tests further isolate North Korea, weaken its economy, and deprive its people," Trump said.

"The United States will take all necessary steps to ensure the security of the American homeland and protect our allies in the region."

U.S. Secretary of State Rex Tillerson warned that Washington "will never accept a nuclear-armed North Korea" and called on Russia and China to do more to curb the growing threat.

Tillerson said Russia and China are "the principal economic enablers of North Korea's nuclear weapon and ballistic missile development program" and bear "unique and special responsibility for this growing threat to regional and global stability."

Earlier, the U.S. and South Korean militaries responded to the ICBM launch by conducting live-fire exercises using surface-to-surface missiles.

Japanese government spokesman Yoshihide Suga said the North Korean missile flew for about 45 minutes — about five minutes longer than the ICBM North Korea test-fired on July 4.

South Korea's military said the missile reached an estimated height of 3,700 kilometers before landing at sea about 1,000 kilometers from its launch site.

It also said that the missile had been fired at a very high trajectory and that it could have traveled much further if fired at a lower trajectory.

David Wright, a physicist and co-director of the global security program at the Union of Concerned Scientists, said in Washington on July 28 that if the Japanese and South Korean reports of the missile's maximum altitude and flight time are correct, the ICBM would have a theoretical range of at least 10,400 kilometers. That means it could have reached Los Angeles, Denver, or even Chicago.

The Pentagon said after the launch that the heads of the U.S. and South Korean militaries discussed possible “military response options."

U.S. General Joe Dunford, Chairman of the Joint Chiefs of Staff, and Admiral Harry Harris, head of the U.S. military’s Pacific Command, spoke with chairman of South Korea’s Joint Chiefs of Staff, general Lee Sun Jin.

Pentagon spokesman Captain Jeff Davis said on July 28 that the United States remains “prepared to defend ourselves and our allies from any attack or provocation.”

Japanese Prime Minister Shinzo Abe said after convening an emergency meeting on the launch that it constituted a "serious and real threat" to the country's security.

Even before the latest launch, tensions were high on the Korean Peninsula, with the United States, Japan, and South Korea repeatedly expressing condemnation of previous test launches by Pyongyang.

North Korea’s nuclear and ballistic-missile programs are banned by United Nations resolutions, but Pyongyang has continued the tests, saying they are necessary to prevent aggression by the United States.

On July 27, U.S. General Mark Miller, the Army chief of staff, warned that the ability of nuclear-capable North Korea to launch a missile that could reach the continental United States was advancing significantly and faster than expected.

Miller said "time is running out” for a diplomatic solution to the crisis over Pyongyang’s weapons program.

The U.S. Senate on July 27 nearly unanimously approved tough sanctions on Russia, Iran, and North Korea and has sent the legislation to the White House pending President Donald Trump's signature.

Washington says the ICBM-type launched on July 4 could likely carry a nuclear warhead and threaten the United States.

That launch came after Trump assailed North Korea’s “reckless and brutal regime” and said there was a “strong, solid plan” to deal with Pyongyang’s illicit nuclear and ballistic-missile programs.

The U.S. Missile Defense Agency said on July 11 that it conducted a successful test from Kodiak, Alaska, of the Terminal High Altitude Area Defense, part of the United States' ballistic-missile defense system.

The agency said a THAAD weapon system detected, tracked, and intercepted a test target, which was similar to missiles recently tested by North Korea.